Originally Posted by W205C43PFL

OP, any luck finding the cause of the issue, hopefully?

Did you also try by using forum member Keith66's method it should help.

Originally Posted by ArtyV

I think it’s just this but he hasn’t answered.

https://mbworld.org/forums/c-class-w...ml#post8556785

Is the Keith thing similar? I’ll check it out later when I get a minute.

Originally Posted by W205C43PFL

I see, try PMing them in the thread and see if they respond that way. If you don't want to do that, you could try mentioning them in the thread instead.
I guess in the mean time, let your service advisor know to check the AC unit for the collapsed hose as mentioned in the thread and see if it takes you anywhere.

Originally Posted by W205C43PFL

OP, any luck finding the cause of the issue, hopefully?

Did you also try by using forum member Keith66's method it should help.

Originally Posted by W205C43PFL

I do apologize but I didn't have luck finding the thread, let's see if we can diagnose this together:
1. Does the sound happen when it is humid and what is the ambient temperature?
2. How frequent this sound occurs?
3. Does the sound comes and goes?
4. Any chance that you can open the hood and hear if the sound is louder when you place your recording device near certain components?
5. Try pushing on components as well.
6. Ignore step 4-5 if it is coming from beneath the engine.

Originally Posted by Keith66

A suggestion is to get a paper towel cardboard tube or something similar on your ear and move around until you can pinpoint the location of the source.